Fig. 1
From: The history and science of Chongkukjang, a Korean fermented soybean product
In Hunmongjahoe (訓蒙字會), Chongkukjang is referred to as si (豉), as seen in jyeonkuk si (from the Japanese Naegakmungobon, 1527) (a), chyeonkuk si (Gyujangkakbon, 1613) (b), and chyeonkguk si (Hankyebon, after 1660) (c). This demonstrates that chongkukjang was called jyeonkuk, chyeonkuk, or chyeongkuk at the time, and written in Chinese character as si (豉)